greefuwalt



2 SHEETSSHEET Patented Dec. 9,1919

J. E. GREENAWALT.

MAGNETIC SEPARATOR.

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J. E. GREENAWALT.

I MAGNETIC SEPARATORf APPLICATION HLED JAN. 3!, I917. RENEWED OCT. 16,1919.

1 32%, 1 %9h Patented Dec. 9,1919.

2 $HEETS-SHEET 2.

Jami-5 233522942; M 6% .VZMWK A T TORJVE l JOHN E. GREENA'WALT, OF NEW YORK, N. Y.

MAGNETIC SEPARATOR.

Specification of Letters Patent.

Patented Dec. 9, 1919.

Application filed January 31, 1917, Serial No. 145,684. Renewed October 16, 1919. Serial No. 331,245.

To all whom it may concern:

Be it known that I, JOHN E. (TKREENAWALT. a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Magnetic Separators, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part hereof.

The present invention is directed to apparatus and processes involving the utilization of magnetic fields for separating magnetic from non-magnetic particles, as for example in the magnetic concentration of ores where the magnetic ore particles or minerals are separated from the non-magnetic material with which they are associated. The invention has for its object to provide an appa-- ratus in which the separating or concentrating process may be carried on under conditions favorable to a thorough and complete removal of the magnetic particles or minerals from the non-magnetic material.

In the practice of my invention use is made of the' buoyant action of liquids in motion whereby they serve not only to hold in suspension the non-magnetic particles but to completely segregate the same from the magnetic particles While'the latter are held under the influence of the magnetic field. Specifically, the invention contemplates Wet magnetic separation, that is to say, separation of magnetic particles from nonmagnetic particles in the presence of a current of water with which the particles are mixed and in which they are more or less suspended, forming what is generally termed pulp. In the present embodiment of my invention the magnetic particles are held to the depositin or concentratlng surface of an endless be t by means of a powerful magnetic field acting through the belt, the belt traveling in a given direction and carrying the magnetic particles with it to a point beyond the magnetic field where the said particles are dropped, the non-magnetic particles and Water of the original pulp being carried in the opposite or different direction whereby the magnetic particles become completely segregated from the nonma etic material. Concurrently With the action of the magnetic field on the magnetic particles, the belt is subjected to an agitation or reciprocating shaking movement in port the U-shaped shoes or bearings a direction preferably transverse to the directions of travel of the belt and of the nonmagnetic component of the pulp, whereby the separating or concentrating action is rendered more perfect and complete, such shaklng movement having the effect of releasing the non-magnetic particles from the magnetic particles held fast to the belt. In the treatment as outlined above, the magnetic particles are influenced by (1) the magnetic field operatincr through the belt or equivalent conveyer; (5) the force of gravitation tending to hold the mineral particles to the concentrating or depositing surface of the belt; (3) the continuous movement of the particles by the continuous movement of the belt; and (4) the shaking or'reciprocating movement of the belt which enables the water to wash away all the non-magnetic particles while the magnetic particles are held firmly against the belt. On the other hand, the non-magnetic particles are influenced by (1) the force of gravitation though in a less degree than are the magnetic or mineral particles by reason of the lower specific gravity of such non-magnetic particles; (2)

the buoyant action of the liquid or water in which the particles are more or less suspended; (3) the shaking or reciprocating movement of the belt which freely agitates the particles, the latter owing to their nonmagnetic character being free to be washed away by the stream of water; (4) the carrying of the particles by the flowing stream to the discharge end of the belt. The ad vantages of the invention will be fully apparent from the following detailed description thereof in connection withthe accompanying drawings in which Figure 1 represents a top plan of the concentrator, parts being broken away; Fig. 2 is a, side elevation thereof; Fig. 3 is a middle vertical longitudinal section on the line 3-3 of Fig. 1; and Fig. 4 is a vertical cross-section on the line 4.4 of Fig. 2.

Referring to the drawings, 1, 1, represent parallel structural members serving supwhich the lower ends of the oscillating links 3 are ivotally secured, the upper ends of the lin s being pivotally coupled to similar shoes or bearings 2 secured to the sides of an oblong frame 6 composed of suitable structural members connected by tie rods 13 well understood in the art. Disposed on one side of the frame 6 near each end thereof are pairs of lugs or ears 7 between which are pivotally secured the inner terminals of suitable eccentric rods 8 the straps, 9 whereof pass around the eccentrics 10 on the main drive shaft 11 mounted parallel to the lon clining downward somewhat from the drum 12 toward the drum 12', to permit the water to carry off to better advantage the nonmagnetic material which has been separated fromthe magnetic particles. This-inclination should be but slight (as shown in the drawings) in order to prevent a too rapid flow of the water' over the depositing surface, thereby allowing the non-magnetic particles ample time to detachthemselves rom the magnetic particles under the shaking action of the belt. By thus reducing the rate of flow of the water over the depositing surface we bring about the accumulation of a maximum or substantial quantity of pulp receiving the benefit of the shaking action aforesaid. Motion is imparted to the belt by a worm shaft 1 1 mounted in the bracket arms 15 carried b the frame 6, the worm pinion 16 on sai shaft meshing with a worm wheel 17 on the shaft 18 of the drum 12. Rotation at any desired speed may be imparted to the shaft 14 from anyconvenient source, preferably however from the shaft 11 by means of-a belt 19 passing over a cone pulley 20 on the shaft 11 and over a similar cone pulley 21 on the shaft 14. The.

direction of travel of the concentrating belt 13 is from. the drum 12' toward the'drum 12, the latter drum dipping into a body of water in a tank 22 which receives the concentrates dropped from the belt at that end. At the opposite end the tailings or nonmagnetic'particles and water with which they are mixed are received in a tailings tank' or receptacle (or launder) 23, the material flowing over the drum 12 directly into the receptacle. The lower lapof the concentrating belt 13 passes over guide rollers 24 disposed below the frame 6, and supported in brackets or hangers 25 carried by said frame as clearly shown inthe drawings. These rollers are sufiiciently elevated to cause the ends of said lower lap to incline downward or dip toward the tanks 22, 23,

respectively, said dip being desired to properly guide the belt lap accross the tanks (Fig. 3). The upper lap of the concen trator belt is supported on rollers 26 mounted on side bars 27 carried by the blocks 28 at each end of the frame 6, said rollers being of iron or steel or equivalent material having a high magnetic permeability, the side bars 27 however being of non-magnetic material such as wood to prevent the short circuiting of the lines of force between the positive and negative poles of'the magnets operating in conjunction with the concentrator belt as will hereinafter. more fully ap ear.

isposed at the terminals of the .I-beams or structural-members 1, are suitable structural members or l-beams 29 to which are secured the posts or standards 30', said posts being well within the frame 6 and removed sufliciently from the sides thereof so as not ,to interfere with the shaking movements of the frame. To the upper terminals of said standards are secured the an le beams 31, the connection being effected y means of angle brackets 32 ,or otherwise (that is immaterial) as best appeals to the skilled mechanic. The horizontal legs of the angles 31 serve to support the yokes 33 of a series of powerful electromagnets 34 (although permanent magnets are not outside the scheme of my invention) the poles of which are presented to the bottom surface of the upper lap of the concentrator belt, the magnets being confined between the belt laps as shown. The poles N, S, of the magnets are alternately positive and negative (that is to say north and south poles) in order that the lines of force may be distributed to the best advantage throughout the entire magnetic field.' In order to accommodate the rollers 26 the several poles of the series of magnets are formed with longitudinal grooves or depressions d, a sufficient clearance being left between the rollers and walls of the depressions to permit of the shaking movement necessarily participated in by the rollers without rubbing against the poles. The pulp is delivered onto the concentrating surface of the belt from a perforated pipe 35' disposed transversely across the middle of the belt close to the concentrating surface, one end of the pipe being closed, the opposite end being adapted to be coupled to any suitable source'of pulp supply (not shown). Between the pulp-feed pipe 35 and the drum 12 and near the end of (but still within) the magnetic field is a similar cross pipe 36, said pipe serving to spray water onto the belt so as to thoroughl wash the concentrates or magnetic partic es adhering thereto before said particles pass out of the influence of the magnetic field.

The operation is obvious from the foregomg description, but briefly stated is substantially as follows: Rotation being: imparted to the drive shaft 11 in proper direction, the upper lap of the concentrator belt Wlll be advanced from the drum 12 toward the drum 12 so as to permit the concentrates to drop from the concentrating surface into the concentrate tank 22. At the same time the frame 6 and necessarily the concentrator belt will have imparted to them a series of quick transverse ,reciprocations or shakin movements as already described. These sha ing movements operate to loosen the non-magnetic from the magnetic particles, which latter tend to separate themselves from the non-magnetic not only on account of the higher specific gravity of said magnetic particles (minerals and metals usually have a higher specific ravity than the gangue or rock with which t ey are associated) but on account of being drawn to and held against the concentrating surface by the action of the magnetic'field operating through the belt. By the time the magnetic particles carried by the belt reach the drum 12 they will have passed outside or be 0nd the influence of the magnetic field, being left free to drop from the belt into the tank 22, the water in said tank washing the particles off the belt before the lower lap passes over the drum 12'. The shaking movement imparted to the frame 6 and to the concentrator belt causes a thorough and quick separation of the non-mag netic component of the pulp from the magnetic particles adhering to the belt, said non-magnetic component flowing down the incline of the concentrating surface of the belt into the vat or tank 23, so that a complete segregation of the magnetic from the non-magnetic particles results. The pulp as it is delivered to thebelt assumes the form of a sheet, said sheet freely flowing toward the drum 12 from which the tailings (nonmagnetic component of the pulp) flow directly into the vat or tank 23. The magnetic particles of course begin to adhere to the belt the moment the pulp strikes the concentrating surface thereof and will be carried with the belt under the spray pipe 36 at which point they will be thoroughly washed before dipping into the water in the concentrate tank 22. I do not of course Wish to be restricted to the details here shown or to the direction or kind of shaking motion imparted to the belt. Features shown but not alluded to are well understood in the art and a description thereof is unnecessary.

Having described my invention what I claim is:

1. In an 'apparatus'of the character de scribed, a suitable conveyer provided with a concentrating surface, means for spreading thereover in sheet form a charge of liquid pulp containing magnetic and nonmagnetic particles, amagnetic field operating to hold the magnetic particles against the concentrating surface whereby they advance with the conveyer, the concentrating surface being pitched or inclined to the horizontal'to' cause the non-magnetic particles to flow in the opposite direction to the travel of the conveyer, said pitch being sufficiently low to materially retard the passage of the pulp along the concentrating surface and retain thereon a body of pulp of substantial depth, and means for subjectin the conveyer to agitation during the perio of its travel whereby the non-magnetic particles sus ended in the water of the pulp are released from the magnetic articles adhering to the concentrating surface.

2. In comblnation with a frame, an endless belt conveyer mounted thereon and having an upper lap traveling in a plane slightly inclined to the horizontal, the upper face of said lap serving as a de ositing or concentrating surface for a c arge of liquid pulp, the pitch of said surface being Suficiently low to materially retard the passage of the pulp thereover and retain thereon a body of pulp of substantial depth, means for imparting motion to the belt, means for imparting to the frame and belt a series of shaking movements or reciprocations transverse to the direction of travel of the belt, rollers disposed across the bottom of the upper lap of the belt for supporting the same, and a series of electro-magnets disposed beneath and adjacent to said upper lap, the poles of said magnets being provided with suitable grooves or depressions for receiving the lower peripheral portions of said. rollers, the latter being composed of material having magnetic permeability.

In an apparatus of the character described, a suitable conveyer provided with a concentrating surface pitched or inclined to the horizontal, means for delivering thereto a charge of liquid pulp containing magnetic and non-magnetic particles, the pitch of the concentrating surface being sufpieptly low to materially retard the passage 0 t e pulp thereover and retain thereon a body 0 pulp of substantial de th, a magnetic field operating to hold t e magnetic particles against the concentrating surface whereby they travelwith the conveyer, and means for causing a disengagement of the non-magnetic particles from the magnetic particles adhering to said surface.

4. In an apparatus of the character described, a suitable conveyer provided with a concentratin surface, means for spreading thereon a c arge of liquid pulp contain= ing magnetic and non-magnetic particles, a magnetic field operating through the conveyer to hold the magnetic particles against the concentrating surface whereby they advance with the conveyer, the concentratint surface being pitched or inclined to the bore zontal, said pitch being sufiiciently low to articles adhering to theconcentrating sur- 10 materially retard the passage of the pulp ace.

along the concentrating surface and retain In testimon whereof I afiix my signature, thereon a body of ulp of substantial depth, in presence 0 two witnesses.

and means for su jecting the conveyer to a itation during the period of its travel JOHN GREENAWALT' w iereby the non-magnetic particles sus- Witnesses:

pended in the water of the pulp are released GEO. A. SALLANS,

and caused to flow away from the magnetic LILLIAN L. FRIED. 

